(patch #68) animation: Fix CPU usage issue

The cancelAnimationFrame function was called with the argument
being undefined, which caused Firefox to increase the CPU usage
and keep it there. The function should never be called here,
since the animation timer is cancelled in another place.
(patch) Respect cross-domain iframes

When adding mouse and touch events, it was looking for parent
windows to detect mouse movements there too. However, when the
iframe with the oCanvas content exists on a different domain
than the parent window, the checks would cause permission errors.
This avoids it by comparing the host of the referrer and the
current host (for the content inside the iframe).
(patch) displayobject/clone: Fix absolute positions for new object

Cloning an object will not give the new object the same parent as
the original object. The new will not have a parent. Because of
this, the new object must not have absolute positions that are
based on the original parent object. To solve this, I decrement
the positions by the absolute positions of the parent object.
Update version number to 2.4.1